Electrical device



May 23,` QSQ. VV K ZWORYWN 2,l59,937

ELECTRICAL DEVICE Original Filed Aug. 5l, 1933 il f f i@ .wow/JLPatented May 23, 1939 PAT OFFICE ELECTRICAL DEVICE Vladimir K. Zworykin,Philadelphia, Pa., assignor to Radio Corporation of America, acorporation of Delaware Original application August 31, 1933, Serial No.687,575, now Patent No. 2,085,406, dated June Divided and thisapplication May 21,

1936, Serial No. 81,004

7 Claims.

application Serial No. 687,575, led August 31,

1933, Patent No. 2,085,406 dated June 29, 1937, and entitled Electricaldevices.

It is well known that radio energy having a short wave length (of'theorder of 10 centimeters, for example) can be focused, reected,dispersed, etc. much the same as light by utilizing lenses, prisms, orthe like, made of a proper material such as paraiiin.

An object of my invention is to provide devices of the above mentionedtype which will be efcient in operation and comparatively cheap tomanufacture.

A further object of my invention is to provide devices of the abovementioned type having quasioptical properties which can be controlled iny accordance with a voltage.

More specifically, an object of my invention is to provide ionized gasor space-charge devices for causing radio energy to be refracted,dispersed, reected, and the like.

Other features and advantages of my invention will appear from thefollowing description taken in connection with the accompanying drawing,in which Figure 1 is a side view of a lens constructed in accordancewith my invention and designed to diverge a radio beam;

Fig. 2 is a view of a modified form of a, lens embodying my invention;

Fig. Bis a view taken on the line of 3--3 looking in the direction ofthearrows; y

Fig. 4 is a view of one embodiment of my'inv'ention designed forreflecting a radio beam;

Fig. 5 is a view of a refracting device utilizing the elements shown inFig. 4;

Fig. 6 is a view illustrating one of the uses for my improved devices.

The embodiment of my invention illustrated in Fig. l comprises anenvelope I which is approximately spherical in form and which is filledwith a gas which can be readily ionized. One electrode of the deviceconsistsof a metal band 3 in the form of a circle painted or depositedin any suitable manner upon the inside of the glass ionized, this regionhaving the shape indicated by the dotted lines. By preference thepressure should be such that the ionized glow will be of the uniformtype found in that region called the positive column. Thischaracteristic discharge is well known to those skilled in the art; itis found at gas pressures varying from several tenths of a millimeter toseveral centimeters of mercury. It will be evident that these dottedlines indicate the distributionof the electric iield inside thecontainer, and, since it is the region within this electric field whichis ionized, the dotted lines also indicate the portion of the gas whichis ionized. The electrodes are shaped and positioned to produce anelectrostatic field of shape corresponding to the required lens action.

It Will be seen that this portion of ionized gas is in the shape of adisc which is thick in the middle and thin at the edge. Since ionizedgas has an index-of refraction which is less than unity for the radiowaves, such. waves will travel through the center of this gas lens morerapidly than through air, and the radio beam will be diverged by thelens.

Various gases or gas mixtures may be used in my lens but in general, oneof the noble gases, such as neon, or a mixture of such gases, will bepreferred.

'Ihe gas pressure may vary within wide limits, but preferably it shouldbe low enough so that the ionized region of the gas will be uniformlyionized. Under this condition, it will be apparent that the lensproperties of the device shown in Fig. 1 will depend mainly upon theshape of the ionized gas region.

From the foregoingdescription it will be understood that the lensproperties of the device shown in Fig. 1 are substantially independentof the shape of' the envelope l, the eiective lens shape beingdetermined by the distribution of the electric iield.

Fig. 2 shows a form of lens utilizing a plurality of circular ,gasllledtubes 23. Each tube has two electrodes 25 therein, one at each end ofthe tube, for impressing an ionizing potential upon the gas. This formof lens may be made either converging or diverging by changing theintensity of the discharge in each tube 23.

If a diverging lens is desired, the intensity of the discharge in theouter tube will be made Ygreater than that in any of the other tubes.The intensity of discharge will be graduated from a heavy discharge inthe outer tube, through a diminishing discharge in the intermediatetubes, to a small discharge in the center tube. If a converging lens isdesired, the discharge in the center tube will be made the heaviest, andthe discharge in the outer tube the smallest.

Fig. 3 indicates how the degree of discharge or ionization in thedifferent tubes 23 may be adjusted. All the tubes may be connected inparallel, as shown, each tube having a different value of resistance inseries with it. Thus, as shown in Fig. 3, the outer tube is connecteddirectly across a voltage source, and the next tubes have resistanceunits 21 of increasing value in series with them, the center tube havingthe largest value of resistance in series with it so that the ionizationdischarge in this tube will be small.

Fig. 4 illustrates a cylindrical mirror comprising a plurality ofgas-filled tubes 29, eachtube having an electrode 3i at each end. Whenthe gas in tubes 29 is ionized, they will act as a mir-1 ror to reflectany radio energy striking them. They may be designed to focus theparallel rays of a radio beam, as indicated in the figure.

Fig. 5 illustrates a prism made up of elements 4I constructed the sameas the tubes shown in Fig. 4. Each tube 4I has an intensity of dischargewhich is different than that of the other tubes, and by means of aplurality of resistors 2l these intensities of discharge are graduatedin the manner described in connection with Figs. 2 and 3.

Fig. 6 illustrates a signaling device it for airplanes or the like. Agroup of gas-lled tubes @9 such as shown in Fig. 5 are connected inparallel and supplied with an ionizing voltage modulated byanidentifying signal. This group of tubes is located on or near theearth at a point where an airplane pilot may wish to determine hisposition. For example, the device may be placed at one corner of alanding eld.

The airplane will carry means for transmitting and receiving a radiobeam. In Fig. 6 there is shown a transmitting reflector il with itsdipole antenna i3 and a receiving reflector l5 with a receiving dipoleantenna Ti. To locate the corner of the landing field, a radio beam willbe transmitted from reiiector li. This beam will be reected from theground and received by rehector l5. If the airplane passes over thedevice im, the reiiected beam will be modulated by the identifyingsignal and the pilot will then know his exact position.

The same apparatus may be employed for locating and identifying ships inthe dark or in a fog. The modulating device i@ will be placed on a sideof a ship and on the outside so that a radio beam reflected from theside of the ship will pass through device 'lil and be modulated by asignal identifying the ship.

It will be understood that a portion of the radio beam will be reflectedfrom the modulating de vice itself instead of from the earth. Thisportion of the beam also will be modulated since both the absorbingability and the reflecting ability of the tubes will vary with thedegree of ionization.

Various other modications may be made'in my invention without departingfrom the spirit and scope thereof, and I desire, therefore, that onlysuch limitations shall be placed thereon as are necessitated by theprior art and set forth in the appended claims.

I claim as my invention:

1. An electrical mirror for ultra high radio frequency energycomprisingl a plurality of straight gas-filled tubes arranged injuxtaposed relation with their longitudinal axes parallel so as to forma semi-cylindrical surface, means for ionizingsaid gas, a beam' of ultrahigh radio frequency energy, and means for impressing said beam on saidtubes whereby parallel rays of said ultra high frequency radio energystriking said surface will be brought into a desired focus.

2. In an electrical device, means for reflecting or refracting ultrahigh radio frequency energy, said means comprising a plurality ofstraight gas-filled tubes placed in juxtaposed relation with theirlongitudinal axes parallel to each other, each of said tubes having apair of electrodes, means connecting respective electrodes in parallel,means for ionizing said gas, a source of ultra high radio frequencyenergy, and means for impressing at least a portion of said energy onsaid tubes whereby said energy is reflected or retracted a desiredamount.

3. An electrical reflector for ultra high radio frequency energycomprising a plurality of straight gas-filled tubes arranged injuxtaposed relation with their longitudinal axes parallel so as to forma semi-cylindrical surface, each of said tubes having a pair ofelectrodes, means connecting respective electrodes in parallel, meansfor ionizing said gas, a source of ultra high radio frequency energy,and means for impressing at least a portion of said energy on saidsurface, whereby the rays o said energy will be brought to a desiredfocus.

4. In aV device for changing the course of a beam of ultra high radiofrequency energy, a plurality of straight tubes filled with gas andplaced in juxtaposed position with their longitudinal axes parallel,means for ionizing said gas, and a beam of ultra high radio frequencyenergy, said tubes being so positioned and arranged in said beam thatthe course of said beam is changed a desired amount.

5. A. device for altering a beam of ultra high radio frequency energycomprising a plurality of straight gas-filled tubes placed in juxtaposedren lation with their longitudinal axes parallel to each other, saidtubes being in the same plane, means for producing discharges ofdifferent relative intensities in said tubes, a beam of ultra high radiofrequency energy, and means for impressing said beam on said tubeswhereby said beam is altered a desired amount by said device.

6. A device for altering a beam of ultra high radio frequency radioenergy .comprising a plurality of straight gas-lled tubes placed injuxtaposed relation with their longitudinal axes in a plane, means forproducing discharges of different relative intensities in said tubes,said intensity of discharge being graduated from a middle tube to anouter tube, a beam of ultra high radio frequency energy, and means forimpressing said l beam on said tubes so as to alter said beam a desiredamount.

7. In combination, means forv radiating a beam of ultra high radiofrequency energy, means for reflecting at least a portion of said beam,a plurality of gas-filled tubes containing free electric chargespositioned between said radiating means and said reflecting means, meansfor controlling said electric charges in accordance with an identifyingsignal to thereby modulate said reflected portion of said beam, andmeans for receiving said reected and modulated portion of said beam.

VLADIMIR K. ZWORY'KIN.

